Metadata Report for BODC Series Reference Number 1984744

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

Narrative Documents

Marianda Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity (VINDTA) 3C

The VINDTA 3C (Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity) is a laboratory alkalinity titration system combined with an extraction unit for coulometric titration, which simultaneously determines the alkalinity and dissolved inorganic carbon content of a sample. The sample transport is performed with peristaltic pumps and acid is added to the sample using a membrane pump. No pressurizing system is required and only one gas supply (nitrogen or dry and CO2-free air) is necessary. The system uses a Metrohm Titrino 719S, an ORION-Ross pH electrode and a Metrohm reference electrode. The burette, the pipette and the analysis cell have a water jacket around them. Precision is typically ± 1 µmol kg^-1 for TA and/or DIC in open ocean water.

Further details can be found in the manufacturer's brochure.

Niskin Bottle

The Niskin bottle is a device used by oceanographers to collect subsurface seawater samples. It is a plastic bottle with caps and rubber seals at each end and is deployed with the caps held open, allowing free-flushing of the bottle as it moves through the water column.

Standard Niskin

The standard version of the bottle includes a plastic-coated metal spring or elastic cord running through the interior of the bottle that joins the two caps, and the caps are held open against the spring by plastic lanyards. When the bottle reaches the desired depth the lanyards are released by a pressure-actuated switch, command signal or messenger weight and the caps are forced shut and sealed, trapping the seawater sample.

Lever Action Niskin

The Lever Action Niskin Bottle differs from the standard version, in that the caps are held open during deployment by externally mounted stainless steel springs rather than an internal spring or cord. Lever Action Niskins are recommended for applications where a completely clear sample chamber is critical or for use in deep cold water.

Clean Sampling

A modified version of the standard Niskin bottle has been developed for clean sampling. This is teflon-coated and uses a latex cord to close the caps rather than a metal spring. The clean version of the Levered Action Niskin bottle is also teflon-coated and uses epoxy covered springs in place of the stainless steel springs. These bottles are specifically designed to minimise metal contamination when sampling trace metals.

Deployment

Bottles may be deployed singly clamped to a wire or in groups of up to 48 on a rosette. Standard bottles and Lever Action bottles have a capacity between 1.7 and 30 L. Reversing thermometers may be attached to a spring-loaded disk that rotates through 180° on bottle closure.

Dissolved Inorganic Carbon and Total Alkalinity CTD and Underway bottle data for UK SOLAS CRUISE D326

Originator's Data Acquisition and Analysis

The sampling procedure of samples collected from CTD casts during SOLAS cruise D326 for the determination of dissolved inorganic carbon (DIC) was according to DOE (1994). Briefly, samples were immediately collected from the CTD Niskin bottle following sampling for trace gases. The sample was delivered from the Niskin bottle to a borosilicate glass bottle (250 ml) using silicon tubing. The sample bottle was firstly rinsed and then the silicon tubing was placed at the bottom of the bottle and filled with sample and subsequently allowed to overflow by at least half a bottle volume to ensure all air bubbles had been removed. The glass stopper was inserted into the glass bottle in order to remove the stopper volume and a 1% (2.5 ml) headspace to allow for water expansion. The sample was poisoned with a saturated solution of mercuric chloride (7 g/100 ml) in a 0.02% volume ratio (50 µL) in order to prevent any biological activity in the stored sample. The bottle was air-tight sealed and then stored in a cool and dark place until analysis. DIC samples were generally analysed within less than two days after sampling and water for alkalnity measurements were stored for analysis back at the National Oceanography Centre.
Samples were collected following a similar procedure from the ships underway toxic system.

DIC Analysis
Analysis was conducted using a coulometric titration which used a Marianda VINDTA 3C (Kiel, Germany) connected to a UIC Inc coulometer. The sample is acidified with 10% phosphoric acid which converts total dissolved inorganic carbon to carbin dioxide gas which is subsequently carried into the coulometeric cell using an inert gas (N₂) and titrated coulometrically. Precision (mean standard deviation n>3) was found to be 0.04% (> 2 µmol/kg)

Total Alkalinity determination
During the cruise analysis for the determination of total alkalinity (TA) had to be postponed until back at the National Oceanography Centre due to a communication failure between the titration unit and computer. After determination of DIC, the samples were well sealed and kept for TA analysis back ashore.
TA anlysis involved the titation of the sample with hydrochloric acid (0.1 M).The acid solution is added in small increments until the carbonic acid equivalence point is reached (protonation of carbonate and bicarbonate ions). The total volume added allows the calculation of total alkalinity to be undertaken. A glass electrode/reference electrode system monitors the titration (mesuremnt of the electromotive force).

References cited

DOE (US Department of Energy) 1994. Handbook of methods for the analysis of the various parameters of the carbon dioxide system in sea water. Version 2, A. G. Dickson and C. Goyet, eds. ORNL/CDIAC-74.

BODC Data Processing Procedures

Data were received by BODC in Microsoft Excel spreadsheet format; one file with seperate worksheets for underway measurements and CTD cast data (Data_for_BODC_Solas_D326_Cynthia_Dumousseaud.xls). The CTD data worksheet contained the following metadata fields: cast ID, Day, Time, Latitude, Longitude, Niskin bottle number and bottle depth. The underway data worksheet contained the following metadata fields: event, day, time, day+time, latitude and longitude.

Parameter codes defined in the BODC parameter dictionary were mapped to the variables as follows:

The data were then banked according to BODC standard procedures for sample data. Once tagged with the appropriate parameter code and, if necessary, converted to BODC standard unit for that parameter, the data are loaded into BODC Samples Database. In this process, sample metadata are checked against information held in the database. Discrepancies are investigated and, when necessary cross-checked with the data originator prior to correction.

Data Quality Report

No advice concerning the data quality was received by BODC from the originator. During BODC processing no standout data points were noted.

Project Information

UK Surface Ocean Lower Atmosphere Study

The UK Surface Ocean Lower Atmosphere Study (UK SOLAS) is the UK's contribution to the international SOLAS programme.

UK SOLAS formed interdisciplinary teams to address three primary aims

• To determine the mechanisms controlling rates of chemical transfer and improve estimates of chemical exchanges
• To evaluate the impact of these exchanges on the biogeochemistry of the surface ocean and lower atmosphere and on feedbacks between the ocean and atmosphere
• To quantify the impacts of these boundary layer processes on the global climate system

UK SOLAS started in 2003, to run for seven years. The programme was funded by the Natural Environment Research Council.

Funded projects

In total, 19 projects have been funded by UK SOLAS, over four funding rounds.

UK SOLAS has also supported ten tied studentships, and two CASE studentships.

Fieldwork

UK SOLAS fieldwork has included eight dedicated research cruises in the North Atlantic Ocean. Continuous measurements were made aboard aboard the Norwegian weather ship, Polarfront, until her decommission in 2009. Time series have been established at the SOLAS Cape Verde Observatory, and at the Plymouth Marine Laboratory L4 station. Experiments have taken place at the Bergen mesocosm facility.

A series of collaborative aircraft campaigns have added complementary atmospheric data. These campaigns were funded by UK SOLAS, African Monsoon Multidisciplinary Analyses (AMMA-UK), Dust and Biomass Experiment (DABEX) and the Facility for Airborne Atmospheric Measurements (FAAM).

Weblink: http://www.nerc.ac.uk/research/programmes/solas/

Data Activity or Cruise Information

Data Activity

BODC Sample Metadata Report for D326_CTD_16390A

Please note:the supplied parameters may not have been sampled from all the bottle firings described in the table above. Cross-match the Sample Reference Number above against the SAMPRFNM value in the data file to identify the relevant metadata.

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: D326_CTD_16390A

Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.